A new analytic model to simulate the electrical behavior of a snow-covered insulator

One of the most serious problems associated with snow and ice accumulation is insulator flashover. Though considerable research has been done on flashover of ice-covered insulators, there was relatively little on insulators covered with snow. So, further research was required on the electrical behavior of snow-covered insulator to yield an analytic model of the voltage-current characteristics of a snow-covered insulator. Based on experimental work more than one hundred different tests, the electrical characteristics of snow were evaluated and a precise mathematical model for simulating its behavior under alternating voltage, at 60 Hz power frequency, was developed. This model shows that voltage across snow is a logarithmic function of the leakage current of snow depending on snow density and conductivity of the water melted from snow. It was found there is good concordance between the simulated voltagecurrent characteristics of snow and those obtained experimentally.

Keywords:

Snow , Density , Conductivity , Flashover , Non-linear resistance , Analytic model